An orthogonal frequency division multiplexing (OFDM) scheme has been known as a multiplexing scheme for efficiently using is frequency bands. In the OFDM scheme, a guard interval is added to the beginning of an OFDM symbol. The guard interval is provided for preventing interference occurring between symbols due to influence of a delayed wave. When a delayed wave exceeding the guard interval is received, the reception quality deteriorates significantly due to the interference between symbols. In this respect, a longer guard interval is conventionally set in consideration of a possible maximum delayed wave (refer to Patent Document 1).    Patent Document 1: Japanese Patent Application Publication No. 2005-318636